Tube and header joint



Filed May 24, 1949 R MW M M Q 2 a /A Patented Mar. 2, 1954 Andre H'uet, Paris; France, assignor to Oomb'us tion Enginceringylncg New York; N. Y.,-'a corpcration of helaware Application: Ma er 1949, Serial No. 94,947 1 Claim: (01. 285 -163) The. present inventionrelates. to a. iointgfor detachably connectingthe. tubes orelemen-ts .of a

heat exchanger to the headers of. said-exchanger. the type of connection being. of such .design that it is fluid tight even.in.case..of yariations'off temperature and in cases where highpressure jointsare required.

In heat exchangers. such .aswaterreheaters or economizers where .the fluid that. flows. inside the. tubes, of the exchanger. is, water, the various portionsof the Joint between the tube .and the header do. notucoollnrhat. up with the same.

rapidity since. thecoefilcient of heat transmission between. water .and meta1.is..-very great. jAsa resultv of this,.the. surfaces .in.co ntact. at the? joint may occasionally be separatedj'from each other, particularly when the. water. within. the tube is underhigh pressure, and thiscanses;leak-.

age, erosion and Lrapid destruction .of "the joint..-

Inorder'to. overcome these disadvantages, I have designed a joint for connecting tubes to headers. that forms-the .object...of .the. present invention. According to this, the end of the tube that is to be detachably connected to the headerwis machined so asto iform a male 1'01" female conical set-ofi,. anda: corresponding female or male conical set-01f. is nrovidedinzthe header; On all orpart-'of"the. -conicali-setofi surfaces, both of the tube .andithei-iheadenathere are'provided'little circulargrooves whichigive a saw-tooth appearance to theisurfaeesoffz'the set-offs when seen .in. section... Between the two male and female set offs there is fitted a gasket of plastic or elastic metat of-conical shape-and suitably having an angle at the top slightl-y-*different from that of the two conical set-offs. Upon being tightened, the two conical set-offs engage in each other, locking and crushing the metalloplastic gasket between them. This insures a tight joint, even though the surfaces of 21 playv (shown exaggerated'inthe; drawing) between ,the male and female portions;

Figures 4 and .5lrelate to anotherembodiment of the'ioint using a gasket bent in U shape, Figure 4 showing the parts that. form the joint" before assembly and Figure'5 showing on an enlarged scale the respective positions of the variou elements when there might be" play resulting from differences of expansion.

the conical set-offs might momentarily come apart under the effect of variations of temperature.

The method of carrying out the invention will be readily understood from the following description when read with reference to the appended drawings:

Figure 1 is a view in section of the various members that form the joint between a tube and header according to the invention.

Figures 2 and 3 relate to a variant of the joint, Figure 2 showing the parts that form the joint before assembly, and Figure 3 showing on a larger scale the positions of the parts when differences of expansion may produce a certain amount of According to the invention, the tube or ele-'- ment In ofthe exchanger to be joined to the walliof the header I2 is provided withan upset orenlargedend 14 havingits. end shaped as :a male cone frustum' l6. A corresponding female conical seat 18 is provided in'the walloi header 12.. Between" these. two conical parts there is fitted 'agasket 2.0, "e. g. metal-lopl asticof annealed copper, said gasket being of general truncated- I cone shape, and having anangleat the top slight-.-

ly different from, e; g. greaterthan, the angleat thetopof conefrustums IE and l'8;..

Furthermore, an annular seat 22'is provided at the end of cone" Hi," and circular plane seat is similarly provided at the bottom of the female portion I8; Th'e'gasket 20 has a terminal circularycollarflange 26 which applies against theisea-t-H of the maleportionlfi. Accordingto the" invention; part or all of the truncated coneshaped surf-aces- IG and I 8 are'provided with little protuberances obtained-for example, by makingcircular grooves 28, 30 in the wal-lsofthe two cone frustums which then, in;-sections,-have' a toothed shapaasshown in the drawing.

For-locking-oi---'the-joint, a washer 32 applies r against a'= set-off 34-," e: gz-spherical, provided at the base of the male portion IS. The washer 32 of two adjacent tubes may apply against the heads it of th elements in order to effect locking of the joints, this being done through the intermediary of a flange or rider 35, as shown in Figure 1. This flange 36 is locked against Washer 32 by means of a ring 38 transversed by a stud 40 secured in header [2. A nut 42 mounted on the end of the stud 40 impinges against washer 38 which applies the common flange 36 against the washers 32, thus insuring engagement of the male cones I6 in the female seats l8, and at the same time locking the copper gasket 20 between the conical surfaces.

When the locking has been effected, the corrugations provided on the cone frustums l6 and I8 strongly squeeze between them the copper gasket 20 which penetrates into these corrugations and insures tightness. Even when fully locked there is still a certain play between the tightness is thus retained until equilibrium has again been restored, with the two conical portions returning to their normal positions and the inter mediate joint resuming its shape and usual position.

In the variant shown in Figures 2 and he gasket I 29 is of purely truncated cone shape without collar flange, and grooves I28 are provided only in the upper part of cone It at a height of about half the height of cone frustum gasket I28. I'he female portion I8 is provided with grooves I39 at a height of at least half the height of cone frustum gasket I20. The assembling of this joint is effected in the same manner as in the preceding case, and the members take up the positions shown in which gasket I20 is compressed between the set-ofis It and It.

When variations of temperature cause the occurrence of play between the two male and female portions, this play bein shown exaggerated in Figure 3 for the sake of clarity, it can be seen that owing to the grooves I30, the bottom portion of gasket I20 continues to adhere to the female set-off I8, while-the top portion of the same gasket continues to adhere to the male set-off I6 thanks to the top grooves I28. ihegasket I20 then assumes the shape shown'in the drawing, thus insuring tightness in spite of the space formed between the seats I6 and I8.

In order to facilitate the working of the joint, the angle at the top of cone frustum gasket I2!) is slightly greater than the angle at the top of cone frustums I6 and I8. It is of course evident that use may be made of a cone frustum asket I20 having an angle at the top smaller than the angle at the top of cone frustums I6 and I8, but

in this case the arrangement of the grooves I28.

and I30 on the seats I6 and I8 would be reversed,

i. e. the base of cone frustum gasket I20 would adhere to the male set-off I6, and its top portion to the female set-ofi I8.-

Figures 4 and 5 illustrate a variant in which 4 grooves 228 and 230' respectively provided on the seats I6, I8 occupy a height corresponding to the entire height of cone frustum gasket 220. The end of gasket 220 that is directed toward the inside of the header is suitably beveled as shown at 222, so as to facilitate the flow of the liquid within the U-shaped channel 224 of the gasket between the two metal layers of which it is formed whenever expansions cause a spreading apart. Figure 5 shows on an enlarged scale the position of the members when the male seat I6 happens to move away from the female seat I8. In this case, the U gasket 2211 continue to adhere owing to the serrations 228, 230 on the conical set-offs, but it opens slightly as shown in the drawing, this action being facilitated by the effect of the pressure of the fluid which penetrates into th channel 224 in the gasket as a result of the beveling of the top edges of said cular grooves or serrations on the outer end of.

the recess, and along approximately a half of the height of the frusto-conical seat; and a gasket,

preferably of metalloplastic material, adapted to be squeezed between the end of the tube and the.

recess in the header to make a joint, so that, notwithstanding expansions, one half of the gasket continues to adhere to the tube end, and the other half of the gasket to the wall of the recess.

ANDRE HUET.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,789,594 Oven Jan. 20, 1931 1,914,512 Key June 20,1933' 1,926,107 Morehead Sept. 12, 1933 2,407,552 Hoesel Sept. 10, 1946 2,407,553 Hoesel Sept. 10, 1946 2,429,924 Clarke Oct. 28, 1947 V FOREIGN PATENTS Number Country Date 20,635 France July 13, 1918- 

